How to backup LR from two computers on one hard drive

[lettyski]

Hi,
Very green around the ears here. I have backup questions.
I have LR cc on an imac desktop and a MacBook Pro. I use the imac when home and the laptop when traveling. Right now the desktop LR is using 2.2GB (does that mean storage?) and LR on laptop takes up 2.1 GB. I do have an external hard drive constantly connected to the desktop and I have a portable HD that I back up the laptop to, on occasion. Laptop is also backed up with Carbonite.
I would like to be able to work back and forth. Can I download the lr catalog that is on my desktop to a second external hard drive and then be able to plug it into the laptop and see that catalog, my library, and ultimately edit photos that are on the harddrive?
And the reverse. Catalog from laptop placed on external harddrive and then I can work on those photos when the external hard drive is hooked up to the desktop.
I guess what I am wanting is the 2 catalogs to sync. How do you all do that? What kind of external hard drive should I buy? I am also beginning to do video and would need those on another EHD, I imagine.
Thank you for your insight and advice.

 

[clee01l]

Let's distinguish between a backup and LR catalog files. First, an app like Time Machine is the system backup. You can create versioned backups of all of your critical user data including your documents, the LR catalog file, and all of your image files. Backups have one purpose. That is to recover lost, damaged or files that were saved with errors. If you are not using TimeMachine or a similar Backup App, you are at risk the your disk drive does fail (and it will) Lightroom backup catalog files are insurance against database corruption and a fall back to recover from "stupid user mistakes". We all make "stupid user mistakes". I have gone back as far as 6 month to recover from a keywording mistake that wiped out keywords on over 2000 image.
Lightroom catalog file backups do not back up your original image file copies. This is another reason that a system backup app is so important.

Without moving your master catalog to a shared EHD, you can not use your master LR catalog file on two machines. While this can be done, I don't recommend it and it introduces another layer of complexity into the LR workflow and usually, reading and writing to an EHD is slower thant reading and writing to the local disk drive Two catalog files are always out of sync.

Adobe has developed a catalog Export/Import process to merge catalog files. The most effective workflow (that I use) keeps my master catalog file and all of my image files on the local disk or locally attached disks (EHDs) on my iMac. My MBP is used as my travel laptop and I keep on it a travel catalog which I merge into my master catalog when I return home. If I shoot in the field, I import new image files to the travel catalog and on returning transfer this catalog and the newly acquired image files to a transfer EHD to be merged into the Master catalog using the "Import from another catalog" function.